WO2005109958A1

WO2005109958A1 - Microwave storage and heating tray with interior liquid seal and exterior pressure relief

Info

Publication number: WO2005109958A1
Application number: PCT/US2005/010094
Authority: WO
Inventors: Gary L. Hopkins, Sr.; Gary L. Ii Hopkins
Original assignee: Steamway Franchise Sales, Inc.
Priority date: 2004-04-27
Filing date: 2005-03-25
Publication date: 2005-11-17

Abstract

A microwave container for storing and also for allowing for heating of foods within the container. The lid of the container is normally in sealing engagement with the container preventing accidental escape of liquids from the container. Upon heating, the lid is forced to an upward position allowing a limited reduction of pressure within the container as heated moisture is allowed to escape through channels formed in the container rim.

Description

MICROWAVE STORAGE AND HEATING TRAY WITH INTERIOR LIQUID SEAL AND EXTERIOR PRESSURE RELIEF

BACKGROUND OF THE INVENTION The present invention relates generally to the field of containers used in microwave heating of foods. DESCRIPTION OF THE PRIOR ART A variety of plastic containers are available for storing food typically in a refrigerator. The containers include a tub shaped bottom portion with a removable lid. The storage food will inherently contain moisture that may settle in the bottom of the container with the liquid then leaking out in the event the container is tipped onto its side. Various sealing lids have therefore been devised for providing a liquid tight seal. In the event the food within the container is to be reheated, for example, in a microwave oven, the moisture within the food will vaporize causing an increase in pressure within the container. The result is the lid will blow off the container and food may be blown out of the container onto the sidewalls of the oven. There is therefore a need for a container or tray having a lid that will both limit the escape of liquid from within the container in the event the container is tipped on its side while also allowing for the escape of pressure within the container during the reheating cycle. Disclosed herein is such a tray and lid. The container includes a lid movably mounted to the tub containing the food. Normally, the lid is in a downward position relative to the tub providing an interior liquid seal. Once the internal pressure builds, the lid moves slightly upward uncovering channels formed in the tub allowing the steam to escape. I have employed channels formed in the tubs disclosed in my U.S. Patents D420,584; D433,592; D475.571; 6,187,354; 6,309,684; and 6,559,431.

Nevertheless, a tray has not been devised having a movable lid that will both provide an interior liquid seal and an exterior pressure relief means. It is an object of the present invention to provide a new and improved microwave storage and heating tray for use with foods. A further object of the present invention is to provide a microwave storage and heating tray having an interior liquid seal to prevent the accidental escape of liquid from the container. An additional object of the present invention is to provide a microwave storage and heating tray having exterior pressure relief means. Related object and advantages of the present invention will be apparent from the following description.

SUMMARY OF THE INVENTION A microwave storage and heating tray. The tray includes a tub for holding food and a lid movable mounted to the tub. The tub and lid including complementary shaped circumferential edge portions with mating ledges, ridges and grooves allowing the lid to be in either a liquid sealing position or a pressure relieving position. The bottom wall of the tub has a raised portion with a diamond surface reducing the amount of food located centrally in the tub insuring even heating.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of the container tub incorporating the present invention. FIG. 2 is an end view of the tub of Fig. 1. FIG. 3 is a cross-sectional view taken along the line 3-3 of Fig. 1 and viewed in the direction of the arrows. FIG. 4 is a cross-sectional view taken along the line 4-4 of Fig. 2 and viewed in the direction of the arrows. FIG. 5 is a top view of the tub. FIG. 6 is a top view of the lid of Fig. 7 mounted atop the tub of Fig. 5. FIG. 7 is a cross-sectional view of the lid. FIG. 8 is a cross-sectional view taken along the line 8-8 of Fig. 6 and viewed in the direction of the arrows showing the lid in a downward and liquid sealing position relative to the tub. FIG. 9 is the same view as Fig. 8 only showing the lid in an upward and pressure relief condition.

DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Referring now more particularly to Figs. 1-5, there is shown a container having a tub shaped main body 20 consisting of a pair of sidewalls 21 and 22 and a pair of end walls 23 and 24 integrally joined to a bottom wall 25. Walls 21-24 extend upwardly from bottom wall 25 to the rim 26 of the tub. The tub may be produced from a variety of materials that do not interact with food placed within the container. For example, any number of suitable plastics may be utilized in forming the tub. A lid 27 shown in Figs. 6 and 7 is removably mounted to the tub of Fig. 1 and may be produced from the same material as the tub. The lid and tub include mating ridges and grooves allowing the lid to be snapped on and mounted to the tub. The ridges and grooves are designed to allow relative motion between the lid and tub prior to complete removal of the lid from the tub in order to allow steam built up within the container to escape during any reheating process. Referring to Figs. 3 and 4, a continuous ledge 28 is formed on the inside surface of sidewalls 21 and 22 and end walls 23 and 24. Ledge 28 is formed by walls 21-24 extending generally horizontally outward at the base of the top rim. The top rim consists of a pair of upwardly extending walls 30 and 31 extending continuously around the tub and being joined together by a continuous horizontal wall 32 thereby forming a downwardly opening U-shaped rim. Wall 31 is offset outwardly from walls 21-24 forming ledge 28. Wall 30 intersects the vertical at angle 70 which is between 5 to 11 degrees. A continuous channel 33 is formed in the upper portion of wall 30 to receive the mating inwardly projecting ridge formed on the lid. Lid 27 includes a generally horizontally extending wall 34 (Fig. 7) that extends upwardly around its circumference to form a lid rim 35 consisting of a pair of upwardly extending walls 36 and 37 integrally joined together by a horizontally extending wall 38. A continuous ridge 39 is formed on the inwardly facing surface of wall 36 and is normally positioned below the outwardly extending channel 33 of the tub rim wall 30 when the lid is in the downward sealing position of Fig. 8. Further, an outwardly extending ridge 40 is formed on the outwardly facing surface of wall 37 with the bottom edge of ridge 40 resting atop sealable upon ledge 28 of the tub. When the lid 27 is in the downward position as illustrated in Fig. 8, the bottom edge of ridge 40 of the lid is in sealing contact with ledge 28 (Fig. 3) of the tub preventing escape of liquid from the container. Ridges 39 and 40 extend continuously around the lid whereas ledge 28 and channel 33 extend continuously around the tub. In order to mount the lid to the tub, walls 36-38 that form a downwardly opening U-shaped rim are mounted atop and to walls 30-32 of the tub rim as illustrated in Figs. 8 and 9. Rim 26 of tub 21 includes a plurality of outwardly facing pressure relief channels that face outwardly and extend from the top wall of the rim to the bottom outward edge of the rim. For example, grooves 50 and 51 are formed in rim 26 (Fig. 5) and extend from wall 32 down to the bottom edge 52 (Fig. 3) of the outwardly facing rim sidewall 30. Likewise, channels 53-56 are formed respectively in the four corners of rim 26 and face outwardly extending from the top wall 32 of the rim down to the lower edge 52 of continuous sidewall 30. Further a pattern of recesses 57-60 are formed respectively in the upwardly facing surface of wall 32 on the four corners of the tube rim 26 and are aligned respectively with pressure relief channels 53-56. Pattern 57 will now be described it being understood that a similar description applies to patterns 58-60. The pattern of recesses 57 include three recesses 61-63 formed in the horizontally extending top surface of top wall 32 of the rim. Each recess 61-63 opens inwardly into the interior cavity of the tub and then extend radially outward terminating approximately midway in wall 32 between the interior sidewall 31 and exterior sidewall 30 (Fig. 3) of the rim. Initially, lid 27 is in the downward position depicted in Fig. 8 providing a pressure tight interior compartment for the container. As pressure within the container builds during the heating process, the pressurized moisture will force lid 27 to the upward position depicted in Fig. 9 with the bottom edge of ridge 40 moving apart from ledge 28. The pressure within the container will be reduced as vapor escapes between walls 31 and 37 when the lid is in the upward position due to the spacing apart of walls 31 and 37 and then through patterns 57-60 between the top wall 35 of lid 27 and the top wall 32 of the tub rim 26. Eventually, the vapor will escape the container passing through channels 50, 51 and also through channels 53-56. Lid 27 (Fig. 6) includes a tab 59 extending outwardly therefrom to facilitate grasping thereby allowing the lid to be pulled upwardly apart from the tub of the container. The four corners of the lid include respectively, patterns of downwardly facing recesses 80-83 that extend radially outward. The recesses are formed in the downwardly facing surface 64 (Fig. 7) of lid wall 35 and extend from wall 37 to wall 36. Some of the recesses overlap and are positioned atop the pattern of recesses 57-60 formed in the tub rim top wall. The bottom tub wall 25 has a center portion 72 extending upwardly toward the lid and surrounded by a diamond patterned inclined surface 73 to reduce the space between center portion 72 and lid 27 and thus reducing the amount of food located in the center of the container allowing for more even temperature of the heated food across the width and length of the container. The vertices of each diamond in surface 73 are rounded to prevent snagging. Raised portion 72 also forms a liquid channel surrounding the portion 72 to allow the liquid to be spooned out of the container. Raised portion 72 may also be provided with a diamond pattern surface. Many variations of the present invention are contemplated and included herein. For example, channel 33 and ridge 39 are described as extending continuously around respectively the tub and lid whereas both the recess and ridge may be discontinuous as they extend in mating fashion around the tub and rim in order to facilitate easy removal of the lid from the tub. An additional variation includes changing the location of the corner channels 53-56 from the four corners to the sides and ends of the tub. Further, a pressure relief channel may be provided in the upwardly facing surface of rim wall 32 leading from patterns 57-60 to channels 50 and 51 to allow for reduction of pressure. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

Claims

Claims:

1. A microwave storage and heating tray with an interior liquid seal comprising: a tub including a bottom wall, a pair of side walls and a pair of end walls integrally joined together forming a cavity for receiving food, said side walls and end walls extend upwardly from said bottom wall and then outwardly forming a ledge, said end walls and side walls further extend generally vertically from said ledge and then outwardly forming a first rim surrounding said tub; and, a lid sealingly mountable atop said tub and having a liquid sealing position and a pressure relieving position, said lid having a generally horizontally extending main wall with a circumferentially extending sealing surface and a second rim complementary in shape to said first rim, said first rim and said second rim including a mating ridge and groove positioned thereon to hold said lid in said second pressure relieving position once pressure within the tray moves said lid from said sealing position, said ledge and said sealing surface mating together sealing said tub and lid together when said lid is in said liquid sealing position.

2. The tray of claim 1 wherein: said bottom wall includes an upraised center portion reducing the space between said center portion and said lid to reduce the amount of food locatable therebetween.

3. The tray of claim 2 wherein: said upraised center portion includes a diamond patterned surface.

4. The tray of claim 1 wherein: said first rim includes a pair of vertically extending rim walls and a generally horizontally extending rim wall located therebetween forming a u-shaped rim channel, said second rim includes a pair of vertically extending lid walls and a generally horizontally extending lid wall located therebetween forming a u-shaped lid channel, said rim channel and said lid channel are complementary in size and shape fitting together.

5. The tray of claim 1 wherein: said first rim includes a first rim wall extending continuously around said tub and upwardly and outwardly of said ledge, said first rim includes a horizontally extending rim wall extending continuously around said tub and outwardly from said first rim wall, said first rim further includes a second rim wall extending continuously around said tub and downwardly from said horizontally extending rim wall cooperatively forming with said first rim wall and said horizontally extending rim wall an inverted u-shaped rim channel; and said second rim includes a first lid wall extending continuously around said lid and upwardly from said sealing surface, said second rim includes a horizontally extending lid wall extending continuously around said lid and outwardly from said first lid wall, said second rim further includes a second lid wall extending continuously around said lid and downwardly from said horizontally extending lid wall cooperatively forming with said second rim wall and said horizontally extending lid wall an inverted u-shaped lid channel receiving therein said inverted u-shaped rim channel.

6. The tray of claim 5 wherein: said second rim wall and said second lid wall include a mating ridge and groove to releasably lock said lid in said pressure relieving position, said second rim wall extends outwardly from the vertical as it extends away from said horizontally extending rim wall, said first lid wall includes an outwardly extending ridge that forms said sealing surface engageable with said ledge when said lid is in said sealing position.

7. The tray of claim 5 wherein: said horizontally extending rim wall includes a plurality of pressure relief recesses opening inwardly into said tub and extending radially outward and located beneath said horizontally extending lid wall, said second rim wall includes a plurality of pressure relief grooves that extend downwardly from said horizontally extending rim wall, said pressure relief recesses and said pressure relief grooves allowing pressure within the tray to reduce when said lid is forced from said liquid sealing position to said pressure relieving position.

8. The tray of claim 7 wherein: said lid includes a plurality of downwardly opening recesses that extend radially outward that are positioned over said pressure relief recesses.

9. A microwave storage and heating tray comprising: a tub including a bottom wall, a pair of side walls and a pair of end walls integrally joined together forming a cavity for receiving food, said side walls and end walls extend upwardly from said bottom wall and then outwardly forming a ledge, said end walls and side walls further extend from said ledge forming a first rim surrounding said tub; and, a lid sealingly mountable atop said tub and having a liquid sealing position and a pressure relieving position, said lid having a generally horizontally extending main wall with a circumferentially extending sealing surface and a second rim complementary in shape to said first rim so said first rim and second rim fit together, said first rim and said second rim including a mating ridge and groove positioned thereon to hold said lid in said second pressure relieving position once pressure within the tray moves said lid from said sealing position, said ledge and said sealing surface mating together sealing said tub and lid together when said lid is in said liquid sealing position.

10. The tray of claim 9 wherein: said bottom wall includes an upraised center portion reducing the space between said center portion and said lid to reduce the amount of food locatable therebetween.

11. The tray of claim 10 wherein: said upraised center portion includes a diamond patterned surface.

12. The tray of claim 9 wherein: said first rim forms a u-shaped rim channel, said second rim forms a u- shaped lid channel, said rim channel and said lid channel are complementary in size and shape fitting together.

13. The tray of claim 12 wherein : said first rim includes a plurality of pressure relief recesses opening inwardly into said tub and extending radially outward and located beneath said second rim which includes a plurality of downwardly opening recesses that extend radially outward that are positioned over said pressure relief recesses cooperatively allowing pressure within the tray to reduce when said lid is in said pressure relieving position.